50 Mr. Davy’s Lecture on some new analytical Researches 
1. Its colour is black, and its lustre not much inferior to 
that of plumbago. 
2. It is opaque even in the thinnest films. 
3. It is very brittle, and affords a deep gray powder. 
4. It is a conductor of electricity. 
5. It does not fuse at a low red heat, and when raised to this 
temperature, in contact with plate glass, it blackens the glass, 
and a grayish sublimate rises from it, which likewise blackens 
the glass. 
6 . When exposed to air at common temperatures, it usually 
takes fire immediately, and burns with a deep red light. 
7. When it is acted upon by water, it heats, effervesces most 
violently, and evolves volatile alkali, leaving behind nothing 
but potash. When the process is conducted under water, a little 
inflammable gas is found to be generated. A residuum of 
eight grains giving in all cases about T 2 ^ of a cubical inch. 
8. It has no action upon quicksilver. 
9. It combines with sulphur and phosphorus by heat, without 
any vividness of effect, and the compounds are highly inflam- 
mable, and emit ammonia, and the one phosphuretted and 
the other sulphuretted hydrogene gas, by the action of 
water. 
As an inflammable gas alone, having the obvious proper- 
ties of hydrogene is given off during the action of potassium 
upon ammonia, and as nothing but gases apparently the same 
as hydrogene and nitrogene, nearly in the proportions in 
which they exist in volatile alkali, are evolved during the 
exposure of the compound to the degree of heat which I have 
specified ; and as the residual substance produces ammonia 
with a little hydrogene by the action of water, it occurred to 
